Internal orifice of the uterus
|Internal orifice of the uterus|
|Posterior half of uterus and upper part of vagina.|
|Latin||orificium internum uteri|
|Gray's||subject #268 1259|
The internal orifice of the uterus (or internal orifice of the cervix uteri or internal os) is an interior narrowing of the uterine cavity. It corresponds to a slight constriction known as the isthmus that can be observed on the surface of the uterus about midway between the apex and base.
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